Starpharma has applied the nanotechnology science of dendrimers to the discovery and development of new treatment options and prevention strategies for major diseases. This program began in the mid 1990s and from the outset had a focus on the prevention of human immunodeficiency virus (HIV) and sexually transmitted infections (STIs) and the development of microbicide candidates. One of these antiviral dendrimers, SPL7013, was selected as a microbicide development candidate and completed a range of preclinical studies. This work culminated in the recent submission by Starpharma of an InvestigationaI New Drug application for SPL7013 gel (VivaGel TM) and the United States Food and Drug Adminisatration (FDA) allowing Phase I safety studies to start. SPL7013, the active ingredient in VivaGel, represented the first time a dendrimer based product has been submitted to the FDA. ReProtect's product, BufferGel TM, is a leading HIV microbicide/spermicide candidate that is well advanced in its developmental program. It is nearing completion of an NICHD-sponsored pivotal contraceptive efficacy trial, and has been selected for an NIAID-sponsored clinical HIV prevention efficacy trial (scheduled to begin in 2004). BufferGel reinforces a natural vaginal protective mechanism, vaginal acidity, by providing sufficient acid buffering activity to resist semen-induced postcoital vaginal neutralization. It has broad spectrum activity against HIV, HIV cellular vectors, a variety of sexually transmitted disease pathogens, other harmful bacterial flora, and sperm. In the field of topical microbicides, the development of combination products offers the potential benefit of presenting multiple lines of defense to the sexual transmission of HIV. To achieve this outcome, Project 1 will seek to develop a product that combines ReProtect's BufferGel technology and Starpharma's dendrimer based polyanion SPL7013 to provide a topical microbicide candidate with two modes of action against HIV and STIs; a dendrimer based antiviral and pH control. Starpharma's relationship with ReProtect will see this microbicide candidate taken forward as a joint venture development between the two companies and so will combine Starpharma and ReProtect's topical microbicide development skills.